What is the purpose of the punchouts in a jamb shield?

Many older doors did not come with deadbolts. Our Jamb Shield has knockouts so that the holes will line up with almost any lock placement. Door Armor will fit locks that are spaced from 4-1/2-inches to 21-1/2-inches in the center. Also, many apartments now require privacy locks (2nd deadbolt that opens only from the inside). Our Jamb Shield works on many doors with this configuration. Did this answer your questions? Thank you for your feedback